Everyone knows this is true. For one, there are several obvious negative statements that pretty much everyone knows are true and can easily prove (“George W. Bush is not the President,” “Red is not the same color as blue,” “Carlos Mencia is not funny,” etc.). On a less mundane level, whether a statement is positive or negative is a matter of how it is constructed—every positive statement (p) can be restated as a negative (~ ~ p).

And yet you will still hear people—smart people—resort to the obvious fallacy that you cannot prove a negative. Most commonly, you hear it in discussions of atheism. I’m sure even I have resorted to such a claim in my defenses of atheism. Even the brilliant Daniel Dennett erroneously invoked it here to explain why he couldn’t disprove God:

“You can’t prove a negative… I think it was Bertrand Russell who once said that he couldn’t prove that there was not a teapot orbiting Mars. So he’s a teapot agnostic. I’m a teapot agnostic with regard to God, too. I can’t prove that God doesn’t exist.” Continue reading →